Apparatus for distilling hydrocarbons under pressure and a catalyzing agent



A fil 1927. 7

p 19 F. M. HESS APPARATUS FOR DISTILLING HYDROCARBONS UNDER PRESSURE AND A CATALYZING AGENT Filed Sept. 29. 1922 2 Sheets-Sheet 1 Patents w. is, 127.

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rnanois M. Base, on wnrrrne, rirnrana.

APPARATUS FOR DISTILLI NG HYDRGEARBONS UNDER BRE SSUEE AND A AGENT.

Application filed September The-present invention relates to the art of hydro-carbon distillation, and more specifically involves a cracking apparatus substantiallysimilar to that disclosed in an application filed by me June 7, 1922, Serial N 0. 566,470. The apparatus of my present invention is designed to combine the possibilities of cracking under pressure with a further cracking of the distillateproduced by scrubbing the same in the vapor state with a volatile catalyzing agent at a substantially constant and uniform reduced I scrubber in which the pressure, whereby certain important advantages and economies are efi'ected, as set forth later in the present specification.

One important feature ofmy present invention resides in the employment with a still and primary and secondary dephlegmators or vapor-scrubbing chambers, of an automatic pressure-regulating valve in the vapor conduit between said dephlegmators capable ofbeing manually set to different pressures and. boiling ranges, but which, when set acts automatically to maintain the pressure and boiling range within narrow limits and substantially constant.

In order that the invention may be fully understood by persons skilled in the art, I have, in the accompanying drawings, illustrated one practical and preferred form of apparatus which embodies the principle of the invention in regard to both process and physical structure; and referring thereto Fig. 1 is an elevation, partly in vertical section and broken out, illustrating a complete apparatus embodying my invention;

Fig. 2 isa simllar view, on an enlarged scale, of the automatic pressure-regulating apparatus;

Fig. 3 is an enlarged vertical section through one of the vapor tubes of the dephlegmator; and v Fig. 4 is a'detail view showing the appli ,cation of a second automatic pressure regulator to the vapor discharge line of the catalyzing dephlegmator.

Referring to the drawings, and first describing the principal parts or elements of .the complete apparatus, R designates a residuum tank on which is mounted a boiler or still designated as an entiretyby S. D designates as an entirety the primary dephleg'mator and scrubber, and D similarly designates a secondar dephlegmator and distillate in the vapor ea'ranrznae a, 1922. Serial at. 591,215.

state is subjected to further cracking by scrubbing the same with a volatile catalyzing agent. C designates a vapor condenser, '1 an overhead oil tank which maintains a uniform gravity head on the material flowing through the system, and Z designates a receiving drum for the condensed distillate. All of these parts, except the secondary dephlegmator D are structurally substantially identical with corresponding parts disclosed in my aforesaid application Serial No. 566,470, and no claims thereto specifically are made herein but for a full understanding of the present improvements, these parts will be briefly described.

The boiler or still '8 comprises two internested groups of hollow zigzag heating plates, of which only the left hand group is indicated at 16 in Fig. 1; thesegroups forming between them a continuous zigzag channel through which the material in process flows in a thin wide film or stream while undergoing vaporization by the heat furnished by superheated steam entering through a pipe 11 and by the hot residuum from the tank R entering under the pressure existing in the still through pipes 12; both the steam and the residuum traveling upwardly through separate conduits in all. .the hollow heating plates counter-flow to the downward travel of the crude material. The vapors generated in the still are confined by cylindrical tank or bell 13 which completely surrounds and encloses the vaporgenerating apparatus. I

The material in process enters the top of the still through a pipe 15 through the upper portion of which the vapor .passes to the primary dephlegmator and scrubber D, and through the lower portion of which the re- .fiux or condensed vapor in the dephlegmator flows back into the still to be revaporized, along with the material in process.

The. primary dephlegmator D comprises a cylindrical tank 16 divided by transverse tube "sheets, or diaphragms 17 and 18. into upper, intermediate and lower compartments 19, 20 and 21, respectively. Extending be compartment 21 to the upper compartment 19. These tubes 22 preferably contain spirals 23, as shown in the detail view, Fig. 3,

by which the vapor flowing upwardly through the tube is caused to follow a serpentine path. inwardly of the innermost group of vapor tubes is disposed a similar circular group of tubes 2t which constitute residuum conducting tubes. To the lower diaphragm 18 is secured a large tube section or manifold 25 that encircles and communicates with the lower ends of the residuum tubes 2st; and the manifold 25 is connected by a pipe 26 and a union coupling 27 with a residuum flow pipe 1% from the still conveniently located within the vaporflow pipe and the bottom of the dephlegmator tank is connected by a pipe 28 and coupling 29 with the pipe 15 leading from the top of the still. i

interposed in the pipe 15 is a flanged 'l'-coupling 15, from the upper side of which vapor conducting pipes 30 and' 31 lead into the upper portion of the lower compartment- 21 preferably at diametrically opposite points of the latter.

Fitted into and depending from the lower diaphragm 18 and connnunicating with the intermediate chamber is a pipe 32 for the discharge of the material in process from the intermediate chamber 20 to the lowermost chamber 21; and in this pipe 32 is a regulating valve 33 having a stem extending through a packed hearing in the cylindrical wall of the tank, by which the flow of the material in process is regulated,

- Secured to the upper diaphragm 17 and encircling the upper ends of the residuum tubes Ql and communicating with the latter 1s a large pipe section or manifold 35, similar to the manifold and extending laterally therefrom is a residuum flow pipe 36 leading over into the condenser C.

Extending centrally through the upper head of the dephlegmator tank 16, through the upper compartment 19 thereof and its contained manifold 35. and intoand nearly to the bottom of the intermediate compartment 20 is a supply pipe 37 which conducts the material in process into the dephlegmator l). Preferably and as herein shown, the lower end of the pipe 37 is closed, and said pipe is provided with perforations or small apertures 38 that extend practically the full length of that portion of the pipe lying within the central chamber 20 and allow the incoming oil to trickle through and build up in the space around the vapor and residuum tubes. In the upper end of the ipe 37 is a valve 39 having a stem l0 by which the amount of oil entering the perforated pipe 37 may be controlled at will.

The apparatus thus far described is substantially identical with that disclosed in my aforesaid application; but the vapor in the upper chamber 19 of the dephlegmator, instead of passing thence directly into and through the condenser C, as in the apparatus of the aforesaid application, is passed through a secondary dephlegmator D, located at a higher level than the primary dephlegmator D, in which it is subjected to a further scrubbing in the presence of a catalyzing agent.

The secondary dephlegmator D is structurally quite similar to the primary dephlcgmator 1), and comprises a closed cylinder or tank 41 iuteriorly divided by transverse tube sheets or diaphragms 42 and -13 into upper, intermediate and lower compartments 4 1, 45 and d6, respectively. Extending between and at their ends rolled into the (lin phragms -12 and 43 'are several circular groups oi vapor tubes 47. similar to the tubes 22 of the dephlegmator D and preferably containing internal spirafls similar to those shown in detail in Fig. 3.

Connected into the upper chamber 19 of the dephlegmator D is a vapor. delivery pipe 48 which leads into one side of the housing 49 (Fig. 2) of an automatic pressure'regulating valve; and from the other side of said valve housing the vapor is conducted by a pipe 50 into the lower compartment 46 of the secondary dephlegmator D; said pipe 50 extending to nearly the bottom of said compartment.

Into the upper end of the chamber 46 is led a pipe 51 through which a liquid catalyzing agent, such as aluminum chloride liquelied by heat and in amount usually from three to ten per cent of the distillate produced may be pumped; and on one side of. the catalyzing chamber 46 is an opening 52 closed by a detachable cover plate 53, which opening may serve as an inspection and cleanout opening, and also for the purpose of introducing a catalyzing agent in solid or crystalline form, if preferred, when the apparatus is shut down. In the upper portion of the catalyzing chamber 46 is located a conical basin or funnel 54 having a central hole 55; and directly beneath the latter are two internested groups of zigzag heating plates 56, similar to those in the still S, and supplied with superheated steam through inflow and outflow pipes 57 and 58. The vapors flowing through the pipe 50 enter the bottom of the chamber 46 where they mingle with the catalyzing agent, tend to vaporize any liquid lying in the bottom of the chamber, and rising flow through the hole 55 of the basin 54: and enter the tubes 47. With the catalyzing agent in a vapor form, the oil vapors are scrubbed with it in the dephlegmating area, and some reflux with all the catalyzing agent is 'reliquefied and trickles down onto the heating plates 56, the heat of which latter, together with the heat from the vapor entering the chamber through the pipe 50, suflices to revaporize the reflux and catalyzing agent.

In the bottom of the catalyzing chamber iso 46 is a pipe 59 controlled by a cook 60, through which sludge and spent catalyzer is periodically-drawn OE and the chamber can be emptied at any time for inspection, test or repairs.

Extending centrally through the upper head of the catalyzing dephlegmator D is a pipe 61 structurally and functionally simi-) lar to the pipe 37, said pipe extending to nearly the bottom of the intermediate chamber 15;, being closed at its lower end and provided with a series of apertures 62 through which the oil trickles into and builds up in the intermediate chamber, flowing from the bottom ofthe latter into the perforated pipe 37 of the primary'deplegmator through a lateral pipe 63 and elbow coupling 6%. 1n the upper end of the pipe 61 is'a valve 65 similar to the valve 39 and having a stem 66 by which it is manually controlled.

The crude material flows by gravity from the overhead levelling tank T through a lateral pipe 67 and elbow coupling 68 into perforated pipe 61.

The uncondensed vapor accumulating in the upper chamber 44; of the catalyzing 'dephlegmator flows thence through a pipe lower compartment 74. Inwardly of the innermost group of vapor tubes is disposed a group of tubes 76 which constitute ducts for the downward flow of residuum. To the upper diaphragm 70. is secured a large tube section or manifold 77 that encircles and communicates with the residuum tubes 76, and into which the residuum-conducting pipe 36 is led. Secured to the lower diaphragm 71 and encircling the lower ends of the residuum tubes 76 and communicating with the latter is a large pipe section or-manifold 78, similar to the manitold 77; and from the bottom of the manitold. 78 a residuum-discharge pipe 79 leads through the lower head of the condenser cylinder and thence to any suitable point of discharge or storage. In the pipe 79 is a flow-regulating valve 80 having a stem 81 by which it may be manually manipulated.

From the lower end of the condenser tank the. distillate flows through pipes 82 and 84 controlled by a cock 8 1 to vent the uncondensible gases. At 85 is indicated a device for controlling the level of the distillate in the condenser C, which levelling de- V106, since it forms no part of the present invention, is not herein shown and described in detail, but is disclosed and claimed in another application filed b "me on the 29th day of December, 1921, serial No. 525,597.

The crude material enters the system through a supply "pipe 86 equipped with a cock 87 and a check valve 88. The pipe 86 communicates with the lower portion of the intermediate chamber 73 of the condenser C; and from the upper end of said chamber the oil flows by a pipe 89, controlled by a float valve 90, into the overhead levelling tank T.

From the lower end of the receiving drum Z the distillate flows "to storage through a pipe 91 and a cook 92.

For manipulating the valves 65, 33 and 39 from the neighborhood of the valves 84,

92, 80 and 87, the valve 65 is provided with operating connections comprising miter gears 93, 94c, rod 95, miter gears 96, 97 and rod 98; the valve 33 is provided with operating connections comprising miter gears 99, 100, rod 101, miter gears 102, 103, and rod 10%; and the valve 39 is provided with miter gears 105, 106, and rod 107, miter gears 108, 109, and rod 110. r

In Fig. 2 1 have illustrated the detail structure of an automatic pressure-controlling valve mechanism which may be em- 100 ployed to vmaintain substantially. constant any predetermined pressure in the still 3* and primary dephlegmator D; this pressurecontrolling device ,being located in the vapor flow pipe connecting the top of the dephlegmator D witht-he catalyzing chamber 46 of the secondary dephlegmator D. Referring to Fig. 2, in the valve casing 49'is a partition 111 dividing the same into two chambers 112 and 113, the former of which communicates with the pipe 48 and the latter with the pipe 50. The partition or diaphragm 111 is formed with a valve seat 114 with which co-operates a ball valve 115 'on the upper end of a sliding valve stem 115 116. 117 designates a hollow four-way union, in the upper side of which is connected a pipe 118, this latter being joined at its upper end to the lower side of the valve casing 49 through ..a coupling 119 axially bored to form a guide for the valve stem I 116. On the lower end of the valve stem 116 is a plunger 120 slidably fitting the pipe 118. Connected into the lower side of the or union 117 is a depending pipe 121, connected to the lower end of which by a coupling 122 is a pipe section 123 of smaller diameter. Lying opposite and parallel with the pipes 121 and 123 is a vertical pipe of the same diameter as thepipe 123 and compris-.

ing lower and upper sections 12 1 and 125 coupled by a three-way union 126. The lower ends of the pipe sections 12 1 and 123 are joined by a horizontal pipe section 127 and elbow couplings 128 and 129. Into the lateral branch of the union 126 is connected a pipe 130 in which is included a cock 131; and to the outer end of the pipe 130 is connected by an elbow coupling 132 a vertical pipe 133. Into one lateral branch of the union 117 is connected a horizontal pipe 131 closed at its outer end by a cap 135, which cap is tapped axially to receive the threaded stem 136 of aplunger 137 slidably fitting the pipe. 134. The outer end of the plunger stem 136 is equipped with a hand wheel 138.

Into the left branch of the union 117 is 2 connected an elbow pipe 139 carrying a cock 111 and a pressure gauge 112.

lly opening cock 131. the system is filled with glycerine or a light lubricating oil up to the level of the bottom of the plunger 120. The cock 131 is then closed, and morcury is added on top of the glycerin or oil in pipe 125 until the pressure created by the column of mercury is approXimately what is desired on the cracking system. llith the cock 14:1 open, this pressure is indi ated 011 the gauge 14:2. The ball valve 11:") is thus seated under the pressure indicated by the gauge. Vapors in the pipe 18 flow into valve chamber 112 and exert a force on ball valve 115, unseating the latter and flowing thence into valve chamber 113 and pipe 50. The downward movement of the. valve 115 causes a slight movement of the plunger 120. This, in turn, raises the mercury column and increases the pressure on the gauge, the latter showing the exact pressure at which the system is operating at any given time. it the pressure shown on the gauge is not what is desired, it can be changed to suit by an inward or outward :uljustmcnt. through hand wheel 13S, 01' the pressure adjusting plunger 130 which obviously raises the mercury column and increases the pressure when adjusted inwardly, and lowers the mercury column, decreasing thepressure, when adjusted outwardly. After the desired pressure has been obtained by manipulation of the plunger 137, the functioning of the valve and the principles involved may be explained as follows.

As long as the flow remains substantially constant, the position of the valve will remain unchanged. Should the still produce a much larger volume of vapors, due to increased firing, the pressure would rise and the flow would further open the valve 115. But this increases the height of the mercury column which, in turn, increases the resistance or back pressure on the valve. This builds pressure on the system and likewise increases the boiling point of the liquid distilled. Increasing the boiling point decreases the volume, and consequently the valve eventually returns to its former position. When the other extreme takes placethe volume of vapor coming from the still decreasing, then the valve. partially closes. This lowers the mercury column and lowers the resistance or back pressure on the valve. The lower pressure in the still decreases the boiling point and consequently increases the volume of vapor, so that the valve soon returns to its former position. Thus it is seen that the valve not only holds the pressure in the. still within a desired limited range, but that it also is an automatic aid to smooth running conditions of the still, acting as a cushion and a check, aiding the still when the latter lags and curbing the still when it tends to race.

The operation of the system is probably apparent to persons familiar with the art from the foregoing (ltSClll'JllOfi, but may be briefly summarized as follows.

The cock 8? being open, the teed stock to be cracked is forced by a pump from an outside source through line 86 past check valve 88 into the illlIClll'lCtlltltQ chamber o'l condenser C, filling the space around the tubes of the latter. Thence the oil continues upwardly through line 89 past float valvetlt) into the overflow tank '1, in which a constant level is maintained. From tank T the oil flows by gravity through pipe (if and elbow 68 into the perforated pipe 61, and by manipulating valve 'the amount entering the latter is controlled at will. The perforations in said pipe allow the incoming oil to trickle therethrough and build up around the vapor tubes in the intermediate chamber of the catalyzing dephleginator I) so that the coldest portion is on the top and the hottest portion is at the bottom, with the body of oil moving from the top to the bottom countercurrent to the up ard travel at the oil and ratalyzer vapors. From the bottom of the intermediate chamber of the catalyzing dephlegmator the. oil flows through pipe (33 and elbow (51 into the perforated pipe 37 ot the primary dephlegmater D, the amount being controlled by manipulation of the valve 39, and the oil building up in the intermediatechamber in the same manner in the secondary dephlegmator D, and abstracting heat from 0 the upwardly flowing vapors and residuum. 1

From the bottom of the intermediate chainber 20 the oil flows through pipe 32 into the bottom chamber 21 of the dephlegmator. \Vith a constant flow enterii'ig through pipe 37, the height of oil in the intermediate chamber of the dephlegmator may be controlled at will by the regulating valve 33. This in turn determines the time required for the oil to pass through the chamber, or, in other words, the length of time it is in still where the reflux is again vaporized together with such'portionof the feed stock as will vaporize at the operating temperature and pressure. The operating temperature and pressure are determined by the character of the oil, being lower with light oils and higher with heavy oils, and the pressure is established and rendered substantially constant by the automatic pressure-controlling valve as already described,

In the catalyzing chamber 46 the vapors carried by the resi uum flowing there- 'through is likewise imparted to the feed mingle with the catalyzing agent and flowupwardly through the tubes of the dephlegmat-or D, wherein the catalyzing agent and a part of the vapors condense and fall back to be revaporized by the heating device located in the chamber 46. From the cham-x ber 44 the uncondensed portion of the vapors flows through pipe 69 into and through the condenser G. wherein it is liquefied, giving up its heat to the feed stock flowing countercurrent through the latter. lln the condenser, primary dephlegmator, and residuum flow pi e 14 such heat as is stock. lit will thus be observed that the apparatus embodies a highly eflicient system of heat exchange, the feedstock absorbing heat from the vapors and residuum in both the condenser and the primary'dephlegmator, and also absorbing heat from the vapors in the secondary or catalyzing dephlegmater, and the conservation of heatv thus secured constitutes one of the important results obtained by the invention.

By manipulating the valves 65 and 39, the feed in chamber 45 ,is so adjusted that none of the catalyzing agent is allowed to come over into the vapor 'flow line 69 and the temperature of the vapor escaping through line 69is low enough to insure a good grade of distillate produced. The temperature of the vapors coming over through lines 48, 49 and 50-must be such that full advantage can be taken of the catalyzing power of the agent used, without, on the other hand, allowingany liquid to build up in the tubes of the secondary dephlegmator D. Any catalyzing agent desired may be usded, a suitable agent being aluminum chlon e.

Where it is desired to operate the secondary or catalyzing dephlegmator at 'a pressure greater than atmosphere, another automatic pressure-controlling device similar to that already described would be employed, and in Fig. 4 I have indicated the presence of such a device applied to the vapor discharge line 69 leading from the catalyzing dephlegmator.

Among the advantages gained by combining cracking under pressure with the use of a volatile catalytic agent may be mentioned the following:

(l) A greater portion of high boiling points may be changed. to low boiling points with a corresponding pressure.

(2) The undesirable portions of cracked distillate'present when using pressure only, and whichmust be removed by agitation with other chemicalsebefore the same can be used commercially are absent when employing a catalytic agent.

The resultant distillate is a more stable compound that does not deteriorate upon aging.

(4) A continuous cracking unit is afforded, emplo ing a catalytic agent in the vapor state, an a unit so constructed that the catalytic agent may. be removed when exhausted and be renewed Without putting the unit out of operation.

I claim: r

l 1. In a crackingsystem of hydrocarbon distillation, the combination of a still, a primary dephlegmator, a vapor conduit leading from said still to said pnimary dephlegmator, a secondary dephlegmator, a ing' from said still to said primary dephlegmator to said secondary dephlegmator, and means for introducing a catalyzing agent into the presence of the vapor in said secondary dephlegmator.

2. In a cracking system of hydrocarbon distillation, the combination of a still, a

primary dephlegmator, a vapor conduit leading from said still to said primary de- 'said last-named vapor conduit.

3. In a cracking s stem of hydrocarbon distillation, the combination of a still, a primary dephlegmator, a vapor flow pipe connecting said stilland primary dephlegmator,

'a secondary dephlegmator, a vapor flow ipe connecting said primary and secon ary dephlegmators, means for introducing a catalyzing agent into the presence of the vapor in said secondary dephlegmator, and means in said-secondary dephlegmator' for revaporizing the reflux of said vapor and catalyzer.

4. In acracking system of hydrocarbon distillation,-the combination of a still, a primar dephlegmator, a vapor flow pipe connectmg 'said still and primary dephleg- H mator, a secondary dephlegmator, a vapor flow pipe connecting said primary and secondary dephlegmators, means for introducing a catalyzing agent into the presence of the vapor 1n said secondary dephlegmator, means in said secondary dephlegmator for revaporizing the reflux of said vapor and catalyzer, and an automatic pressure controlling device interposed in said last-named vapor flow pipe.

5. In a gravity system of distilling hydrocarbons under pressure, the combination of a still, a primary dephlegmator at a higher level than said still, a vapor flow pipe connecting said still and primary dephlegmator, a secondary dephlegmator at a higher level than said primary dephlegmator, a vapor flow pipe connecting said primary and secondary dephlegmators, means for introducing a catalyzing agent into the presence oi? the vapor in said secondary dephlegmator, means in said secondary dephlegmator i'or revaporizing the reflux of said vapor and catalyzer, an automatic pressure-controlling device interposed in said last-named vapor flow pipe, and means 'for conducting the feed stock successively through said secondary and primary dephlegniators to said still connterflow to, and out of contact with, the

eaaaev vapors flowing through said primary and secondary dephlegmators.

6. in a gravity system of distilling hydrocarbons under pressure, the combination of a still, a primary dephlegmator at a higher level than said still, a vapor flow pipe connecting said still and primary'dephlegmator,

device interposed in said last-named vapor flow pipe, means for conducting the feed stock successively through said secondary and primary dephlegmators to said still counteri'low to, and out of contact With, the vapors flowing through said primary and secondary dephlegmators, and manually operable valves for regulating the flow of the feed stock through said secondary and primary dephlegn'iators.

FRANCIS M. HESS. 

